Properties of Polyacrylate/Bentonite Superabsorbent Hybrid Prepared by Intercalated Polymerization

Abstract

A hybrid superabsorbent consisting of polyacrylate intercalated bentonite was prepared by solution polymerization with an intercalation step, polymerization and a cross-linking reaction. Partially neutralized acrylic acid was intercalated, polymerized and cross-linked to bentonite. The initiator was potassium persulfate and the cross-linking agent was sugar (from Artemisia seed gum). The structure of the polyacrylate/hybrid was determined by FT-IR and XRD. The results showed that the bentonite was intercalated by the polyacrylate. The layer spacing of the bentonite was enlarged. Various factors, (such as the degree of neutralization, the consumption of monomer, the amount of initiator and cross-linking agent and the amount of bentonite), which affected the resin's water absorbency were studied through orthogonal experiments. In optimum conditions the ratio (by weight) of bentonite to monomer was 1/2, the degree of neutralization was 75% (mol), the initiator content was 3%, and the cross-linker content was 5%. The cost of the superabsorbent was decreased by 30%, whereas its water absorbency was about 120 g/g for water, and 30~36 g/g for saline solution.